A femto device (e.g., an access point base station), hereinafter a “femto,” may be a miniaturized base station designed to serve a scaled down area. The scaled down area may be a home or a small business. A femto may incorporate a functionality similar to a base station, but with a modification allowing a self contained deployment. The femto may be connected to the Internet via cable, DSL, on-premise fiber optic link, or a similar IP backhaul technology. This connection is used to integrate the femto with a WAN wireless operator's core network.
A femto may serve a geographic area, known as a “femto cell,” over a single carrier or channel. A femto cell typically covers a smaller geographic area or subscriber constituency than a conventional macro cell (e.g., a base station cell area). For example, femtos typically provide radio coverage in geographical areas such as one or more buildings or homes, whereas conventional base stations provide radio coverage in larger areas such as an entire cities or towns. The function of a femto is similar to that of a Wireless LAN (Local Area Network), providing the operators a low cost solution for coverage extension and for offloading a mobile station from the cellular network.
A shortcoming of a conventional femto is that there is no communication between the femto and other network elements (e.g., a server) regarding the current capacity at the femto. Instead, a network element must attempt to contact the femto for each event. An event may be a call. For example, if the femto is operating at a maximum and/or full capacity, an incoming call may result in a call failure. Thereafter, the network element has to determine a call treatment for the failed call. The call treatment may be a loss of the call (e.g., redirecting an incoming call to a voice mail system) since capacity is not available at the femto. These call originations and/or failures may continue until resources are available at the femto. This redundant operation results in an inefficient utilization of network resources.
Another shortcoming of a conventional femto is that a there is also no communication between a mobile station and the femto regarding the current capacity at the femto. For example, when a mobile station attempts a call via a femto, the call may not go through if the femto is operating at maximum capacity. Furthermore, there is no mechanism to allow the same outgoing call to pass once resources are available at the femto.